Fixed Parser

The framework provides a default hardware parser for common packet types and packet structures. When the protocols supported by the hardware parser meet user requirements, you can use the hdr_fix_parser provided in the hydra_parser.hdr architecture file instead of implementing a custom parser. In this case, parsing is executed by the hardware, which simplifies programming and enhances performance.

header_union l3_union_t {
    ipv4_t                ipv4;
    ipv6_t                ipv6;
}

header_union l4_union_t {
    tcp_t                 tcp;
    udp_t                 udp;
    icmp_t                icmp;
}

header_union tunnel_union_t {
    vxlan_t               vxlan;
    geneve_t              geneve;
    nvgre_t               nvgre;
}

struct hdr_fix_headers {
    ethernet_t            ethernet;
    vlan_t                vlan;
    l3_union_t            l3;
    l4_union_t            l4;
    tunnel_union_t        tunnel;
    ethernet_t            inner_ethernet;
    vlan_t                inner_vlan;
    l3_union_t            inner_l3;
    l4_union_t            inner_l4;
}

Example

• You can use hdr_fix_parser() as the parser component to instantiate the package. In this case, the hdr_fix_headers structure needs to be passed as an input parameter of control to enable the utilization of the parsing results within the control logic.
• You cannot customize the hdr_fix_headers structure or the hdr_fix_parser component. The compiler will check the structure and parser component accordingly.

The following is an example of using the fixed parser:

control MyPrePipe(in hdr_fix_headers hdr) {
    /* body omitted*/
}
control MyPostPipe(in hdr_fix_headers hdr) {
    /* body omitted*/
}

RX_OVS(
hdr_fix_parser(),
MyPrePipe(),
MyPostPipe()
) main;